Loose oem cat-back with aftermarket headers??

[Mk5upra]

Anyone experience a loose oem cat-back after having a aftermarket downpipe on for awhile? Had it on for 2.5 years now. The oem catback does not hold on tight to the downpipe anymore. The bolt is as tight as it can be, but you can still move the cat-back back and forth after removing the lower bolt. Downpipe shrinkage or oem cat-back expanded? First time experience this with all my cars having an aftermarket downpipe. The downpipe does not move except from the flex part.

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[calmeda1]

Did you find out it was loose upon checkage or louder sound?

 

[XtremeMaC]

Which downpipe

 

[Mk5upra]

Found out after the faint exhaust hole noise going by any close walls and when speeding up. Can also hear a metal rattling noise. I'm assuming it's hitting each other (oem cat-back and downpipe).

It's a powerneedy brand. Not bashing on the brand. Going to try putting the oem back on to see if it holds on tight or if it'll be loose also. It's a pain when you don't have a lift. The car does have about 39k miles.

 

[NitroYellowMKV]

Clamp could have failed.

 

[FuzzyRev]

Clamp could have failed.

THIS. Those bandclamps are known to fatigue and crack over time. In addition to that, BMW tells us that they're a one time use, so replace it if you have to unhook it for any reason, as it'll never be as tight the second time around, no matter how much you turn the bolt.

 

[Mk5upra]

THIS. Those bandclamps are known to fatigue and crack over time. In addition to that, BMW tells us that they're a one time use, so replace it if you have to unhook it for any reason, as it'll never be as tight the second time around, no matter how much you turn the bolt.

Kind of weird that they would spot weld it onto the cat-back if that's the case of going bad.

 

[jtsang25]

THIS. Those bandclamps are known to fatigue and crack over time. In addition to that, BMW tells us that they're a one time use, so replace it if you have to unhook it for any reason, as it'll never be as tight the second time around, no matter how much you turn the bolt.

Which one is this one?

 

[MYA90SUPRA]

Which one is this one?

I'm guessing it's the clamp that's at the beginning of the catback. It is spot welded to the exhaust.

 

[Mk5upra]

Which one is this one?

 

[FuzzyRev]

The spot-weld is for ease of assembly on the line. Just because something left the factory a certain way doesn't mean the replacement parts will be packaged the same. I mean, look at our exhaust as a whole. It comes OE as a single, welded assembly, but the replacement system is split into two unique sub-assemblies with special clamps to seal them together. There's tons of examples like this throughout the industry.

 

[Mk5upra]

The spot-weld is for ease of assembly on the line. Just because something left the factory a certain way doesn't mean the replacement parts will be packaged the same. I mean, look at our exhaust as a whole. It comes OE as a single, welded assembly, but the replacement system is split into two unique sub-assemblies with special clamps to seal them together. There's tons of examples like this throughout the industry.

Spot-weld for ease of assembly, but if you remove the old clamp (prying it off) for a new one you will have to grind the spot weld down so it can sit flush. You can just clamp over it but you will now have a gap in that spot or can move it pass the spot-weld I guess.

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